1. Field of the Invention
The present invention relates to a recombinant yeast having a predetermined gene introduced therein and a branched alcohol production method using the recombinant yeast.
2. Background Art
In recent years, the following problems have been arising regarding ethanol used as automotive fuel: the energy density thereof is low and the characteristics thereof significantly differ from those of conventional petroleum fuel. Therefore, studies have been conducted to produce butanol or the like, which is an alcohol with an extended carbon chain length serving as fuel characteristically closer to petroleum fuel, by a fermentative production method with the use of Escherichia coli and yeast (see WO 2007/041269 and WO 2008/052991). In addition, since a gasoline fuel with the high octane number of such a straight-chain alcohol is preferably used, fuels comprising 2-methyl-1-butanol, 3-methyl-1-butanol, and the like have been also studied (Nature 451, 86-89, (2008)).
Meanwhile, it has been reported that 2-methyl-1-butenol can be synthesized by causing the expression of the nudF gene or yhfR gene of Bacillus subtilis in Escherichia coli. In addition, it has been revealed that expression products of the nudF gene and the yhfR gene convert dimethylallyl-diphosphate or isopentenyl diphosphate into 2-methyl-3-butene-1-ol (Appl. Environ. Microbiol. 73, 6277-83 (2007)). Further, it has been reported that 3-methyl-2-butene-1-ol and 3-methyl-3-butene-1-ol can be synthesized by causing the expression of the above genes in Escherichia coli in a similar manner (WO 2007/139925).